Q.
In a guitar, two strings A and B made of same material are slightly out of tune and produce beats of frequency 6 Hz. When tension in B is slightly decreased, the beat frequency increases to 7 Hz. If the frequency of A is 530 Hz, the original frequency of B will be :
A) 524 Hz
B) 536 Hz
C) 537 Hz
D) 523 Hz
Explanation
[Solution] $f_B$ = 524 or 536 Hz. Lowering tension lowers $f_B$; the beat frequency rises only if $f_B$ was below $f_A$, so $f_B$ = 524 Hz. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.